1. Field of the Invention
This invention relates to a data carrier, in particular paper of value, bank note, ID card, credit card, telephone card or the like, having a serial number consisting of several characters which uniquely individualizes the data carrier from a series of data carriers, and to a numbering apparatus for numbering the data carriers.
2. Related Technology
To increase security and to identify documents, for example bank notes, checks, ID cards, credit cards or the like, one applies consecutive numbering, usually printing this so-called "serial number" on the completed data carrier. For applying the serial number to the data carriers one uses for example a numbering unit placed in a numbering station which the documents pass through for numbering.
DE-OS 1 486 894 discloses a numbering printing unit for providing such documents with a consecutive serial number. This multidigit number can be provided on the document several times and be applied horizontally or vertically, the number being printed with a special ink, for example a magnetic ink.
To increase security in documents of value, EP 0 061 795 B1 further proposes providing the printed serial number with an additional code number which varies with the consecutive numbering and is printed in a different color from the serial number.
For further improving the security of numbered documents, EP 0 160 504 B1 has proposed designing the serial number so that at least two characters of the serial number differ in height, width, type font or in a combination of these properties.
The invention is based on the problem of proposing a numbering apparatus and documents numbered with this numbering apparatus whereby the security of the documents is improved by the numbering with the numbering apparatus.
This problem is solved by the features of the independent claims.